currently ggplots appear one after another in the rendered HTML code, and the visual layout is determined interactively, by resizing/zooming the window. layout here means how to arrange the ggplots in a grid (is plot 3 to the right of plot 2, or below plot 1?)
would be nice if we could implement some simple method for defining the layout.
for example below plots are in a 2x2 table, plot1 is on the first/left column, spanning both rows; plot2 is on the second/right column, first row; plot3 is on the second/right column, second row.

animint(
  plot1=ggplot()+theme_animint(row=1, col=1, rowspan=2)),
  plot2=ggplot()+theme_animint(row=1, col=2),
  plot3=ggplot()+theme_animint(row=2, col=2))